Running the website in a Staged Environment

Hi, so, the company I started working in wants me to change the layout/overall design of their website and they gave me access to the cPanel of the website; and I can tell that the developers used wordpress.

But before I do that, of course, I need to set up a back-up where I can do experiments or at least be able to have a rollback option.

The problem is, there is no backup button here:

/http://i.imgur.com/vOZooYt.png

Also, even if I downloaded the files manually, how can I run the website on my own computer?
I've exported the database and it's over 80MB and importing only allows around 10mb.

I use xampp apache and WindowsXP 32-bit (cause other computers not available)

Ultimately, I want to run the whole website in my PC

Please help provide me some insights it would be very much appreciated

Some users prefer to setup a development version of their website by creating an Addon domain name in cPanel or by creating a separate cPanel account. It's an alternative to consider if you prefer to avoid setting up a web server on your personal computer.